Soft-sided bulk material storage container

ABSTRACT

In accordance with presently disclosed embodiments, a stackable bulk material storage container is provided. The bulk material storage container includes a panel-less frame having a top portion and a bottom portion, which is supported by cross bracing. A hatch is coupled to the top portion of the frame. The hatched is opened when loading the bulk material into the container and closed during transport. A gravity feed outlet is coupled to the bottom portion of the frame. The outlet is opened to dispense the bulk material out of the container and closed during transport. A containment structure is further provided, which has a greater storage capacity over conventional containers. The containment structure is defined by an upper portion formed of a soft material and a bottom portion formed of a rigid material. The containment structure is attached to the frame at least at the hatch and the gravity feed outlet.

TECHNICAL FIELD

The present disclosure relates generally to the handling of dry bulk materials, and more particularly, to a soft-sided bulk material storage container for use in the storage, transportation and dispensation of such dry bulk materials.

BACKGROUND

During the drilling and completion of oil and gas wells, various wellbore treating fluids are used for a number of purposes. For example, high viscosity gels are used to create fractures in oil and gas bearing formations to increase production. High viscosity and high density gels are also used to maintain positive hydrostatic pressure in the well while limiting flow of well fluids into earth formations during installation of completion equipment. High viscosity fluids are used to flow sand into wells during gravel packing operations. The high viscosity fluids are normally produced by mixing dry powder and/or granular materials and agents with water at the well site as they are needed for the particular treatment. Systems for metering and mixing the various materials are normally portable, e.g., skid- or truck-mounted, since they are needed for only short periods of time at a well site.

The powder or granular treating material is normally transported to a well site in a commercial or common carrier tank truck. Once the tank truck and mixing system are at the well site, the dry powder material (bulk material) must be transferred or conveyed from the tank truck into a supply tank for metering into a blender as needed. The bulk material is usually transferred from the tank truck pneumatically. More specifically, the bulk material is blown pneumatically from the tank truck into an on-location storage/delivery system (e.g., silo). The storage/delivery system may then deliver the bulk material onto a conveyor or into a hopper, which meters the bulk material through a chute into a blender tub.

Recent developments in bulk material handling operations involve the use of portable containers for transporting dry material about a well location. The containers can be brought in on trucks, unloaded, stored on location, and manipulated about the well site when the material is needed. The containers are generally easier to manipulate on location than a large supply tank trailer. The containers are eventually emptied by dumping the contents thereof onto a mechanical conveying system (e.g., conveyor belt, auger, bucket lift, etc.). The conveying system then moves the bulk material in a metered fashion to a desired destination at the well site.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an isometric view of a soft-sided bulk material storage container, in accordance with an embodiment of the present disclosure;

FIG. 2 is a cutaway perspective view of the soft-sided bulk material storage container shown in FIG. 1 revealing the inside of a containment structure of the bulk material storage container;

FIG. 3 is a top isometric view of the containment structure illustrating cross-bracing tensioner panels which reinforce an upper portion of the containment structure, which is formed of a soft material;

FIG. 4 is a cross-sectional view of an attachment mechanism used to secure a top of the upper portion of a soft-sided containment structure to an inlet comprising a hatch; and

FIG. 5 is a cross-sectional view of an attachment mechanism used to secure the bottom of the soft material forming the upper portion to a rigid material forming a lower portion of the containment structure.

DETAILED DESCRIPTION

Illustrative embodiments of the present disclosure are described in detail herein. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation specific decisions must be made to achieve developers' specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of the present disclosure. Furthermore, in no way should the following examples be read to limit, or define, the scope of the disclosure.

Certain embodiments according to the present disclosure may be directed to systems and methods for efficiently managing bulk material (e.g., bulk solid or liquid material). Bulk material handling systems are used in a wide variety of contexts including, but not limited to, drilling and completion of oil and gas wells, concrete mixing applications, agriculture, and others. The disclosed embodiments are directed to systems and methods for efficiently moving bulk material into a blender inlet of a blender unit at a job site. The systems may include a portable support structure used to receive one or more portable containers of bulk material and output bulk material from the containers directly into the blender inlet. The disclosed techniques may be used to efficiently handle any desirable bulk material having a solid or liquid constituency including, but not limited to, sand, proppant, gel particulate, diverting agent, dry-gel particulate, liquid additives and others.

In currently existing on-site bulk material handling applications, dry material (e.g., sand, proppant, gel particulate, or dry-gel particulate) may be used during the formation of treatment fluids. In such applications, the bulk material is often transferred between transportation units, storage tanks, blenders, and other on-site components via pneumatic transfer, sand screws, chutes, conveyor belts, and other components. Recently, a new method for transferring bulk material to a hydraulic fracturing site involves using portable containers to transport the bulk material. The containers can be brought in on trucks, unloaded, stored on location, and manipulated about the site when the material is needed. These containers generally include a discharge gate at the bottom that can be actuated to empty the material contents of the container at a desired time.

In existing systems, the containers are generally supported above a mechanical conveying system (e.g., moving belt, auger, bucket lift, etc.) prior to releasing the bulk material. The discharge gates on the containers are opened to release the bulk material via gravity onto the moving mechanical conveying system. The mechanical conveying system then directs the dispensed bulk material toward a desired destination, such as a hopper on a blender unit. This process can release a relatively large amount of dust into the air and result in unintended material spillage. In addition, the mechanical conveying system is generally run on auxiliary power and, therefore, requires an external power source to feed the bulk material from the containers to the blender.

The material handling systems having the portable support structure disclosed herein are designed to address and eliminate the shortcomings associated with existing container handling systems. The portable support structure may include a frame for receiving and holding one or more portable bulk material storage containers in an elevated position proximate the blender inlet (e.g., blender hopper or mixer inlet), as well as one or more gravity-feed outlets for routing the bulk material from the containers directly into the blender inlet. In some embodiments, the portable support structure may be transported to the well site on a trailer, unloaded from the trailer, and positioned proximate the blender unit. In other embodiments, the portable support structure may be a mobile support structure that is integrated into a trailer unit. The portable support structure may be designed with an open space at one side so that the blender unit can be backed up until the blender inlet is in position directly under the gravity-feed outlet(s) of the support structure.

The disclosed portable support structure may provide an elevated location for one or more bulk material storage containers to be placed while the proppant (or any other liquid or solid bulk material used in the fluid mixtures at the job site) is transferred from the containers to the blender. The support structure may elevate the bulk material storage containers to a sufficient height above the blender inlet and route the bulk material directly from the containers to the blender inlet. This may eliminate the need for any subsequent pneumatic or mechanical conveyance of the bulk material (e.g., via a separate mechanical conveying system) from the containers to the blender. This may improve the energy efficiency of bulk material handling operations at a job site, since no auxiliary power sources are needed to move the material from the containers into the blender inlet. In addition, the portable support structure may simplify the operation of transferring bulk material, reduce material spillage, and decrease dust generation.

Furthermore, the containers in accordance with the present disclosure are intended to be stackable, when being transported or stored and also when being placed on a frame above a blender or mixer for dispensing. To facilitate their stacking, each container frame must be robust enough to carry the weight of its stack. Furthermore, each frame is equipped with alignment pins to facilitate the stacking of the containers.

Turning now to the drawings, FIG. 1 illustrates a schematic diagram of a soft-sided bulk material storage container 10 in accordance with the present disclosure. The container 10 includes a frame 12, which includes a top 14, bottom 16 and plurality of sides 18. The frame is formed of a plurality of rigid bars 20, which in one exemplary embodiment may be formed of steel. As those of ordinary skill in the art will appreciate, however, alternative rigid materials may be used in the construction of the frame 12. The grade/weight of steel or other rigid material utilized should be able to carry the weight of multiple containers such as when the containers are stacked. A pair of parallel tubes 21 is attached to the bottom 16 of the frame 12 at generally opposite sides, as shown in FIG. 2. The tubes 21 have a general rectangular cross-section and are designed to accommodate the forks of a forklift. This enables the containers 10 to be easily hoisted onto and off transportation units (not shown) and also moved around a well site.

One of the features of the frame 12 is that the rigid bars 20 are formed at least on the sides into a cross-bar configuration. These cross-bars reinforce the frame 12. Unlike prior art bulk material storage containers, whose frames are made up of solid panels, frame 12 simply relies on the cross-bars to give it form and strength. This configuration results in a lighter-weight container 10 which has a greater capacity for storage of bulk material. Indeed, the reduction in material making up the frame 12 together with the use of a soft material for the storage containment structure 22 reduces the overall weight of the container by approximately 31% over prior art containers. This weight savings will allow an approximate additional 2,000 lbs. of dry bulk material to be transported in each container, which results in an approximate 5% increase over current capacity of existing conventional bulk material storage containers. Furthermore, the fabrication expenses associated with the design of the present bulk material storage container 10 will also result in a significant reduction in the fabrication cost for the containers. It is estimated that by eliminating the conventional side panels and associated welding of same, that a reduction of approximately 100 hours of fabrication time will result in connection with the manufacture of the bulk storage material containers 10, in accordance with the present disclosure.

An inlet 24 is located in the top 14 of the frame 12. The inlet 24 is formed by two orthogonal pairs of parallel cross bars. One or more hatches 26 may be mounted to the inlet 24 by a pair of hinges 28 and 30. The pair of hinges 28 and 30 enables the hatch to swing between an open position and a closed position. In the open position, dry bulk material can be disposed into the container 10 through the opening 24. In the closed position, the dry bulk material is contained within the container 10 thereby preventing it from being lost to the environment or exposed to undesired moisture. Bulk material loss can be an issue during transport and in windy environments. Thus, the hatch 26 assists in the containment of the bulk material storage. The container 10 is also formed with a plurality of alignment pins 25 disposed on the top 14 of the frame 12 and an associated plurality of alignment recesses 27 disposed on the bottom of the frame 12. The associated alignment recesses 27 are designed to receive the alignment pins 25 from another container 10 to thereby enable stacking of the containers 10.

The storage containment structure 22 is formed of an upper portion 40 and a lower portion 42, which are best seen in FIG. 2. The upper portion 40 is formed of a soft material. Suitable materials for the soft material include, but are not limited to, a cloth, a canvas, a canvas coated with a rubber material, a canvas coated with an elastomeric material, a woven nylon, woven polyethylene, a vinyl coated polyester, a plastic, a woven glass coated with a rubber material, a woven glass coated with an elastomeric material, a gunny sack and combinations thereof. The bottom portion is formed of a rigid material, which in one exemplary embodiment is a sheet metal. As those of ordinary skill in the art will appreciate, other suitable materials may be used.

The upper portion 40 of the storage containment structure 22 has a top section 44, a mid-section 46 and bottom section 48. The mid-section 46 is formed of a plurality of side panels, which are attached to each other at adjacent corners. The side panels are attached at right angles to each other (i.e., 90° angles). The top section 44 is formed of a plurality of upwardly tapered panels, which are attached on their sides to each other at adjacent corners. The upwardly tapered panels are also attached to the side panels of the mid-section along a bottom perimeter and to a rim 50, which forms part of the inlet 24 and hatch 26 along a top perimeter. The bottom section 48 is similar in shape to the top portion 44. It is formed of a plurality of downwardly tapered panels which are attached to each other at adjacent corners. The downwardly tapered panels are also attached to the side panels of the mid-section along a top perimeter and to the lower portion 42 of the storage containment structure 22 along a bottom perimeter. The bottom section 48 is funnel-shaped and acts to direct the bulk material downwardly towards the bottom of the container 10 and ultimately out of the container upon dispensing.

The upper portion 40 is formed with a first plurality of pockets 50 which are formed along a top perimeter of the mid-section 46 and a second plurality of pockets 52, which are formed along a bottom perimeter of the mid-section 46, as shown in FIGS. 1 and 3. The pockets 50 and 52 are attached to the upper portion 40 by sewing them onto the material forming the upper portion or by use of an epoxy or other suitable chemical attachment means. Thermal processes could also be used for bonding the pocket. Support hangers 54 are disposed in the pockets 50 and 52. The support hangers 54 attach to the sides 18 of the frame 12. They help to give form as well as support to the upper portion 40 of the storage containment structure 22. They also carry the load of bulk material stored within containment structures 22 formed of soft material.

The upper portion 40 of the containment structure 22 may also be formed with a plurality of tensioner members or panels 60, as shown in FIG. 3. The panels 60 are formed in a cross-bracing configuration so as to minimize bulging of the containment structure 22 when it contains bulk material. The panels 60 can be made of the same soft material that forms the rest of the upper portion 40, or alternatively can be formed of a more rigid material. Indeed, in at least one alternative embodiment, the panels 60 are formed of a rigid material.

When the soft material is ;Conned of a cloth, fabric or other similar soft material, the upper portion 40 of the storage containment structure 22 is attached at its top to the frame 12 at the inlet 24, as shown in FIGS. 2 and 4. The attachment is accomplished as follows. An upper end 70 of the soft material forming the upper portion 40 is secured to a rim 72 which forms part of the inlet 24 and to which the hatch 26 is attached, as shown in FIG. 4. The upper end 70 of the upper portion 40 is folded over an upper backing plate 74. An upper portion of the fold is sandwiched between the rim 72 and the upper backing plate 74. A lower portion of the fold is sandwiched between the upper backing plate 74 and a lower backing plate 76. A bolt or other fastening means (not shown) secures the upper end 70 to the rim 72 and upper and lower backing plates 74 and 76.

When the soft material is formed of a cloth, fabric or other similar soft material, the upper portion 40 of the storage containment structure 22 is attached at its bottom to the lower portion 42, as shown in FIGS. 2 and 5. The attachment is accomplished as follows. A lower end 80 of the soft material forming the upper portion 40 is secured to a rim 82 of the rigid material making up the lower portion 42, as shown in FIG. 5. The lower end 80 of the upper portion 40 is folded over the rim 82 with an upper portion of the fold being sandwiched between an upper backing plate 84 and the rim 82. A lower portion of the fold in turn is sandwiched between the rim 82 and a lower backing plate 86. A bolt or other fastening means (not shown) secures the lower end 80 to the rim 82 and the upper and lower backing plates 84 and 86.

The lower portion 42 is formed of a plurality of rigid panels 90, which are best seen in FIG. 2. In one exemplary embodiment, the lower portion 42 is formed of four rigid panels 90, which are interconnected at adjacent corners. Each panel 90 is generally trapezoidal in shape. The rigid panels 90 taper in a downward direction thereby forming a funnel, which is designed to direct the dry bulk material downwardly and out of the container 10 through an outlet 92, shown in FIG. 2. The rigid panels 90 may be formed of a sheet metal or other suitable lightweight and durable material.

It should be noted that the disclosed container 10 may be utilized to provide bulk material for use in a variety of treating processes. For example, the disclosed systems and methods may be utilized to provide proppant materials into fracture treatments performed on a hydrocarbon recovery well. In other embodiments, the disclosed techniques may be used to provide other materials (e.g., non-proppant) for diversions, conductor-frac applications, cement mixing, drilling mud mixing, and other fluid mixing applications.

Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the following claims. 

What is claimed is:
 1. A bulk material storage container, comprising: a frame having a top portion and a bottom portion; an inlet disposed at the top portion of the frame; an outlet disposed at the bottom portion of the frame; and a containment structure defined by an upper portion comprising a soft material and a lower portion comprising a rigid material.
 2. The bulk material storage container of claim 1, wherein the frame further comprises a plurality of sides each of which is reinforced with diagonal bracing.
 3. The bulk material storage container of claim 1, wherein the inlet further comprises one or more hatches which has an open position and a closed position, bulk material capable of being dispensed into the container in the open position and bulk material loss from the container being minimized in the closed position.
 4. The bulk material storage container of claim 1, further comprising an upper end of the upper portion which is secured to a rim of the inlet, the upper end of the upper portion being folded over an upper backing plate with an upper portion of the fold being sandwiched between the rim and the upper backing plate and a lower portion of the fold being sandwiched between the upper backing plate and a lower backing plate.
 5. The bulk material storage container of claim 1, further comprising a lower end of the upper portion which is secured to a rim of the rigid material, the lower end of the upper portion being folded over the rim with an upper portion of the fold being sandwiched between an upper backing plate and the rim and a lower portion of the fold being sandwiched between the rim and a lower backing plate.
 6. The bulk material storage container of claim 1, wherein the upper portion of the containment structure comprises a pair of cross-bracing tension members, which minimize bulging of the upper portion when the containment structure contains bulk material.
 7. The bulk material storage container of claim 1, wherein the lower portion of the containment structure is formed of a plurality of interconnected rigid panels, which taper downwardly to form a funnel.
 8. The bulk material storage container of claim 1, wherein the upper portion is formed of a material selected from the group consisting of a cloth, a canvas, a canvas coated with a rubber material, a canvas coated with an elastomeric material, a woven nylon, woven polyethylene, a vinyl coated polyester, a plastic, a woven glass coated with a rubber material, a woven glass coated with an elastomeric material, a gunny sack and combinations thereof.
 9. The bulk material storage container of claim 1, further comprising a first plurality of hangers arranged along an upper outer perimeter of the upper portion and the first plurality of hangers are attached to the frame.
 10. The bulk material storage container of claim 9, further comprising a second plurality of hangers arranged along a lower outer perimeter of the upper portion and attached to the frame, wherein sidewalls are formed between the upper and lower plurality of hangers.
 11. The bulk material storage container of claim 10, wherein the first and second plurality of hangers are disposed within pockets formed into the upper portion along the upper and lower outer perimeters of the upper portion.
 12. The bulk material storage container of claim 1, wherein the rigid panels attach to the outlet.
 13. A bulk material containment structure, comprising: an upper portion formed of a soft material; and a lower portion coupled to the upper portion, the lower portion formed of a rigid material and having a plurality of interconnected rigid panels, which taper downwardly to form a funnel.
 14. The bulk material containment structure of claim 13, further comprising a pair of cross-bracing tensioner members, which are capable of minimizing bulging of the upper portion when containing bulk material.
 15. The bulk material containment structure of claim 13, wherein the upper portion comprises a lower end which is secured to a rim of the rigid material, the lower end of the upper portion being folded over the rim with an upper portion of the fold being sandwiched between an upper backing plate and the rim and a lower portion of the fold being sandwiched between the rim and a lower backing plate.
 16. The bulk material containment structure of claim 13, wherein the upper portion is formed of a material selected from the group consisting of a cloth, a canvas, a canvas coated with a rubber material, a canvas coated with an elastomeric material, a woven nylon, woven polyethylene, a vinyl coated polyester, a plastic, a woven glass coated with a rubber material, a woven glass coated with an elastomeric material, a gunny sack and combinations thereof.
 17. The bulk material containment structure of claim 13, further comprising a first plurality of hangers arranged along an upper outer perimeter of the upper portion of the bulk material containment structure.
 18. The bulk material containment structure of claim 17, further comprising a second plurality of hangers arranged along a lower outer perimeter of the upper portion of the bulk material containment structure, wherein sidewalls are formed between the upper and lower plurality of hangers.
 19. The bulk material containment structure of claim 18, wherein the first and second plurality of hangers are disposed within pockets formed into the upper portion along the upper and lower outer perimeters of the upper portion.
 20. The bulk material containment structure of claim 13, wherein an upper section of the upper portion is tapered upwardly and a bottom section of the upper portion is tapered downwardly. 